Safety device for elevators.



M. G. SCHWAB.v

SAFETY DEVICE FOR ELEVATORS.

APPLICATION FILED MAR.23, 1909.

Patented Feb. 22, 1910.

2 SHEETS-8KEET 1.

AIMW a, GRAHAM co, Pnatamnoqmwzws. WASNXNGYON v.0.

M. G. SCHWABL SAFETY DEVIGE FOR ELEVATORS.

APPLICATION FILED MAR. 23, 1909.

7; Patented Feb. 22, 191 0.

2 SHEETS-SHEBT 2.

AENT FIG.

MARTIN C. SGI-IWAB, OF CHICAGO, ILLINOIS.

SAFETY DEVICE FOR ELEVATORS.

Specification of Letters Patent.

Patented Feb. 22, 1910..

Application filed March 23, 1909. Serial No. 485,328.

To all whom it may concern:

Be it known that I, MARTIN C. SonwAn, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Safety Devices for Elevators, of which the following is a specification.

An application covering substantially the same subject-matter as the present application was filed April 20, 1907, under Serial No. 369,273, and allowed November 7, 1908.

In an electric traction elevator, the motor is located at the top of the elevator shaft and one end of its armature-shaft projects beyond its adjacent bearing and carries a sheave or drum around which is wound the traction cable, one end of which is attached to the car and the other end of which is attached to a counter-balancing weight. This traction drum is located directly over the elevator shaft and is supported wholly by the projecting end of the armature shaft, so that should the shaft break, the drum, the fragment of the shaft carried away with it and the cable would fall down the elevator shaft with disastrous results.

The object of the present invention is to provide simple and eflicient means for preventing this and to this end I provide an auxiliary support which is normally inactive but which is so related to the drum that in the emergency stated it will catch the drum and hold it. This auxiliary emergency support may be variously constructed and arranged and while three forms of it are shown in the drawings, still, in its broad aspect, the invention is not limited to any of them, since others equally within the scope of the invention will readily suggest themselves to those skilled in the art.

In the accompanying drawings which are made a part of the specification: Figure 1, is a plan view of an elevator system, having a battery of three elevators, embodying the lnvention. Fig. 2, is a vertical section thereof on the line 22, Fig. 1. Fig. 3, is a plan view of portions of a single elevator apparatus embodying the invention under a modification. Fig. 4 is an end elevation thereof, one of the parts being shown partly in section. Fig. 5 is a plan view of portions of a single elevator apparatus embodying the invention under another modification.

Fig. 6 is a longitudinal section of its armature shaft and the shaft of the auxiliary emergency support.

In Figs. 3, 4, and 5 the frame and other parts of the motor are omitted, but it will be understood that they may be of any desired construction, such, for example, as shown in Figs. 1 and 2. Many other parts that are necessary in a complete elevator apparatus are not shown in the drawings for the reason that the present invention is in no wise concerned with them further than that they must be of a construction to which the invention is applicable.

In Fig. 1 the elevator shaft or well is shown at A and the positions of a battery of three elevator cars, B, therein are indicated by dotted lines. At the top of the elevator shaft a motor 0, of any desired construction, for each car, is supported by any suitable means. As shown in the drawings heavy beams, D, are arranged across the elevator shaft and the bases of the motorframes rest upon them, the several motors (where more than one is used) being so arranged that the axes of the shafts, E, of their armatures, F, are coincident. Each motorframe carries suitable bearings, G, for the armature shaft and at one of its ends the shaft projects beyond its adjacent bearing. The projecting end carries a sheave or drum, H, about which the traction cable I, of the car is wound, one end of the cable being attached to the car and the other end to the counter-balance weight, all in customary manner. The projecting end of the armature shaft is subjected to enormous strains, especially when a car is suddenly stopped, and should it break, the drum, the broken ofi fragment of the shaft and the cable will fall down the elevator shaft. To prevent this is the object of the invention and this object is-\preferably accomplished by using a hol- 1 5w... armature shaft and placing within it either a hollow or a solid auxiliary shaft, J. As shown in Figs. 1 and 2 the auxiliary shaft is solid and passes completely through the armature shafts of all of the motors. It is idle and is supported and held centrally within the armature shafts by two supports, K and L, engaging it near its ends and is prevented from moving endwise by pins, j, passed through it and adapted to be engaged by the supports. Should the projecting end of the armature shaft of any of the motors break, the drum, and the broken 0H fragment of the shaft will drop down a short distancesay, a fraction of an inchand be caught by the auxiliary shaft and prevented from falling down the elevator shaft. If it be the shaft of the last motor that breaks, the weight of the drum, etc., suddenly thrown upon the auxiliary shaft will not materially bend or deflect it, because of the close proximity of the drum to the outer support, L, but if it be the shaft of the motor more remote from the end of the auxiliary shaft, the sudden throwing of the weight of the drum, etc., onto the auxiliary may cause it to bend or sag, more or less, and even sulficiently to bring it in contact with the still supported portion of the broken shaft and with the shaft of the adjacent motor. This sag will take place if the auxiliary shaft is long and is supported independently of the armature shaft, (which it must be when it is common to a plurality of motors) but it is a mere incident to the conditions just stated and is neither necessary nor obj ectionable. In any event, it will pass through each drum and will be amply supported on the opposite sides of the drum, either by the supports K and L, or by the armature shafts of the adjacent motors which will still remain supported by their respective bearings G.

The application of the above described form of the invention to a single motor is amply illustrated by Fig. 1, if the second and third motors be considered as absent and the support L be placed in the same relation to the drum of the first motor as it bears to the drum of the third motor, as now shown in the figure. But it is not necessary that the auxiliary shaft be supported independently of the armature shaft, and in the form of the invention shown in Figs. 5 and G the auxiliary shaft is supported by the armature shaft. The two shafts are of about the same length and caps M secured to one and engaging the other, prevent the auxiliary shaft from tumbling around in the armautre shaft or from working out. If desired in addition to the caps, or instead of them, the annular space between the two shafts may be filled with a packing N of any suitable material. With this form of the invention, should the projecting end of the armature shaft break off, it and the drum would fall a short distance, causing the end of the auxiliary shaft to sag until it came in contact with the still supported portion of the armature shaft, whereby it would be supported.

As a further modification of the invention, a suitably supported cradle 0, may be ar ranged immediately below the drum as shown in Figs. 4 and 3. The cradle may be in the form of a hollow casting the top of which is concentric with the face of the drum, the cradle being supported in such position as to leave between it and the face of the drum a space suflicient to accommodate the traction cable wrapped around the drum. l/Vith this arrangement, should the projecting end of the armature shaft break off, the drum will fall into the cradle and be thereby supported.

What I claim as new and desire to secure by Letters Patent is:

1. In an elevator apparatus the combination of a well and a car movable vertically therein, a motor-driven shaft at the top of the well, bearings for said shaft, one end of said shaft projecting beyond its adjacent bearing, a winding drum carried by the projecting end of the shaft, a traction cable wound about said drum and connected with the car, and a normally inactive emergency support arranged in operative relation to the drum and adapted to catch it in the event of the breaking of its shaft.

2. In an elevator apparatus the combination of a well and a car movable vertically therein, an electric motor arranged at the top of the well, bearings for the armature shaft, one end of which shaft projects beyond its adjacent bearing, a winding drum carried by the projecting end of the shaft, a traction cable wound about the drum and attached to the car, and a normally inactive emergency support arranged in operative relation to the drum and adapted to catch it in the event of the breaking of its shaft.

3. I11 an elevator apparatus the combination of a well and. a car movable vertically therein, a winding drum arranged at the top of the well, a traction cable wound about the drum and connected with the car, a hollow shaft carrying the drum, bearings for the shaft, one end of which projects beyond its adjacent bearing, a normally inactive emergency support having an auxiliary shaft arranged within the hollow shaft of the drum.

at. In an elevator apparatus the combina tion of a well and a car movable vertically therein, a motor having a hollow shaft, bearings for the shaft one end of which projects beyond its adjacent bearing, a drum carried by the projecting end of the shaft, a traction cable wound about the drum and connected with the car, and a normally inactive emergency support having an auxiliary shaft arranged within the hollow shaft and means for holding the auxiliary shaft in place.

5. In an elevator apparatus the combination of a well and a car movable vertically therein, a motor arranged at the top of the well and having a hollow shaft, bearings for said shaft, one end of which projects beyond its adjacent bearing, a winding drum carried by the projecting end of the shaft, a traction cable wound about the drum and connected with the car, and a normally in active emergency support having an auxiliary shaft arranged within the hollow shaft and means for supporting the auxiliary shaft in the event of the breaking of the main shaft whereby it is adapted to support the main shaft in the event of the breaking of the latter.

6. In an elevator apparatus the combination of a well and a car movable vertically therein, a motor arranged at the top of the well and having a hollow shaft, bearings for said shaft, one end of which projects beyond its adjacent bearing, a drum carried by the projecting end of the shaft, a traction cable wound about the drum and connected with the car and a normally inactive emergency support having an auxiliary shaft extending through the hollow shaft and projecting therefrom at its ends, and means for supporting the projecting ends of the auxiliary shaft.

7. In an elevator apparatus the combination of a plurality of wells and a plurality of cars movable vertically therein, a plurality of motors arranged over the wells and having hollow shafts arranged with their axes coincident, drums carried by the hollow shafts, traction cables wound about the drums and connected with the cars respectively and a normally inactive emergency support having an auxiliary shaft arranged within the hollow shafts of the several motors and extending from one to another.

8. In an elevator apparatus the combination of a plurality of wells and a plurality of cars movable vertically therein, a plurality of motors arranged over the wells and having hollow shafts arranged with their axes coincident, drums carried by the hollow shafts and arranged over the wells, respectively, traction cables wound about the drums and connected with the cars, respectively, and a normally inactive emergency support having an auxiliary shaft extending through the hollow shafts of the several motors and having projecting ends and supports for the projecting ends of the auxiliary shaft.

9. In an elevator apparatus the combination of a well and a car movable vertically therein, a winding drum arranged over the well, a traction cable wound about the drum and connected with the car, a motor driven hollow shaft carrying the drum, an idle auxiliary shaft'arranged within the hollow shaft, and means for supporting the auxiliary shaft, whereby upon the breaking of the hollow shaft the latter will be supported by the auxiliary shaft.

10. In an elevator apparatus the combination of a well and a car movable vertically therein, a winding drum arranged over the well, a traction cable wound about the drum and connected with the car, a hollow motor driven shaft carrying the drum, bearings for said shaft, said shaft projecting at one end beyond its adjacent bearing, a winding drum carried by the projecting end of the shaft, an idle auxiliary shaft arranged within the hollow shaft and having projecting ends and bearings or supports for the projecting ends of the auxiliary shaft.

11. In an elevator apparatus the combination of a well and a car movable vertically therein, a drum, a cable wound about the drum and connected with the car, a hollow shaft carrying the drum, means for supporting the hollow shaft, an idle auxiliary shaft, disposed within the driven hollow shaft, and means for supporting the auxiliary shaft whereby upon the breaking of the hollow driven shaft, the latter will be supported by the auxiliary shaft.

MARTIN O. SCHWAB. Witnesses L. M. HOPKINS, GRACE A. SOUTHWELL. 

